1. Field of the Invention
The present invention relates to an endoscope apparatus that is used to observe internal portions of an examination subject. Priority is claimed on Japanese Patent Application No. 2009-185760, filed Aug. 10, 2009, the contents of which are incorporated herein by reference.
2. Description of Related Art
An endoscope apparatus provided with a flexible, elongated insertion portion is widely used in order to observe internal portions of a variety of examination subjects (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2008-48946). In this type of endoscope apparatus, an imaging device formed by a CCD or the like is provided on a distal end of the insertion portion. Images acquired by this imaging device are transmitted through the insertion portion to a main unit where they undergo image processing and the like and are then displayed on the display portion of a display unit or the like.
In many cases, light does not reach as far as the internal portions of an examination subject. Because of this, in normal endoscope apparatuses an operation is performed in which the visual field of the imaging device is made brighter (i.e., is illuminated) using an illumination mechanism that includes a light emitting component such as a light emitting diode (LED) or the like. A method in which the visual field of the imaging device is directly illuminated by placing a light emitting component on the distal end portion of the insertion portion, in the same way as for the imaging device, is known as a method for illuminating using an illumination mechanism. Moreover, a method of illuminating the visual field of an imaging device is known in which a light emitting component is placed on the main unit, and illumination light is guided to the distal end of the insertion portion by a light guide that is connected to the light emitting component.
In recent years, in order to make endoscope apparatuses easier to use, devices have been proposed (see, for example, United States Patent Application Publication No. 2009/0109429) in which an operating section that operates the insertion portion and the above described display unit are integrated into a single unit, and that are sufficiently miniaturized that they can be held in one hand. In this type of endoscope apparatus, the operating section, display unit, and main body are united in a single casing. A user uses the endoscope by directly holding the casing.